diff --git a/pyproject.toml b/pyproject.toml
index d7c75537..50f8d47d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,7 +22,11 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Scientific/Engineering :: GIS",
+    "Topic :: Software Development :: Libraries",
+    "Topic :: Software Development :: Libraries :: Python Modules",
     "Topic :: Text Processing :: Markup :: XML",
     "Typing :: Typed",
 ]